Occasion setting of fluid ingestion by contextual cues

Pairing a familiar palatable fluid and a novel context with lithium chloride (LiCl) and presenting the fluid on non-LiCl-paired trials in the home cage resulted in contextual control of fluid consumption: consumption of the LiCl-paired fluid was reduced in the LiCl-paired context but not in the home cage. A nonpaired fluid was consumed normally in the paired context. These results are interpreted as evidence of occasion setting, i.e., the novel context signals a contingency between the fluid and toxicosis but is not itself associated with toxicosis. Pairing the novel context with LiCl prior to fluid-context-LiCl pairings enhanced the development of contextual control of consumption of the fluid. This enhancement is interpreted as summation of excitatory conditioning of the context with its occasion-setting function.